用于前端工作的参考 Model Context Protocol (MCP) 服务器。只需一次安装，即可让任何编码代理（Claude Desktop、Cursor、VS Code、Zed、Continue）真正拥有查看和操作 UI 的“眼睛和双手”：
axe_audit — 针对原始 HTML（通过 jsdom）或实时 URL（通过 Playwright）运行真实的 axe-core 规则引擎。返回按 WCAG 影响程度分组的违规项，并附带修复链接。
page_screenshot — 获取任何 URL 或 CSS 选择器的无头 Chromium PNG 截图，支持视口 / DPR / 配色方案 / waitForSelector 控制。
bundle_budget_check — 遍历 dist/ 目录，计算 gzip（+ 可选 brotli）大小，强制执行全局或每个入口的 KB 预算。提供 CI 就绪的通过/失败 JSON 报告。
design_token_diff — 对两个 W3C DTCG / Style Dictionary 令牌文件进行结构差异对比。报告添加 / 删除 / 修改的令牌，并提供感知 $type 的注释。
storybook_story_run — 通过 iframe.html?id=… 在无头 Chromium 中加载单个 Storybook 故事，进行截图，并仅针对渲染出的组件运行 axe 审计。
scaffold_react_component — 生成带类型的 React 组件（函数式 / forwardRef / 多态 as），以及可选的 Vitest 测试和 Storybook 故事。
所有工具均返回模型可理解的结构化 JSON。无需为每个编辑器编写定制的包装器。
npm i -g @ashios15/mcp-frontend-tools
# Optional — enables page_screenshot, storybook_story_run, and URL-mode axe_audit
npm i -g playwright
npx playwright install chromium需要 Node ≥ 20。即使没有 Playwright，服务器也能启动；如果调用那三个依赖 Playwright 的工具，将返回明确的“安装 playwright”错误。
添加到 ~/Library/Application Support/Claude/claude_desktop_config.json（或 Windows 等效路径）：
{
"mcpServers": {
"frontend-tools": {
"command": "mcp-frontend-tools"
}
}
}设置 → MCP → 添加新服务器：
{
"frontend-tools": { "command": "mcp-frontend-tools" }
}添加到 .vscode/mcp.json：
{
"servers": {
"frontend-tools": { "command": "mcp-frontend-tools" }
}
}npx @modelcontextprotocol/inspector mcp-frontend-toolsRelated MCP server: UX/UI Tools for React + Material-UI
axe_audit{
url?: string; // require playwright
html?: string; // jsdom
tags?: string[]; // default: wcag2a/aa + wcag21aa + wcag22aa + best-practice
selector?: string; // URL mode only
timeoutMs?: number; // default 15000
}返回违规项和不完整规则，包含 impact（影响）、help（帮助）、helpUrl 以及每条规则最多 5 个失败节点示例。
page_screenshot{
url: string;
outPath: string; // absolute; parent dirs auto-created
selector?: string;
fullPage?: boolean;
width?: number; // default 1280
height?: number; // default 800
deviceScaleFactor?: number;// default 2
colorScheme?: "light" | "dark" | "no-preference";
waitForSelector?: string;
timeoutMs?: number;
}bundle_budget_check{
buildDir: string;
budgetKb?: number; // default 250 (gzipped)
perEntryBudgetKb?: Record<string, number>;// key = path substring, longest match wins
ext?: string[]; // default [".js",".mjs",".cjs",".css"]
includeBrotli?: boolean;
}返回每个文件的原始 / gzip / brotli 大小、应用的预算以及 status: "pass" | "fail"。
design_token_diff{
beforePath: string;
afterPath: string;
ignoreKeys?: string[];
}理解 W3C DTCG 结构（$value, $type）。以 $ 开头的组元数据键将被忽略。颜色 / 尺寸的变化会带有 note 注释。
storybook_story_run{
storybookUrl: string; // e.g. http://localhost:6006
storyId: string; // e.g. components-button--primary
screenshotPath?: string;
runAxe?: boolean; // default true
viewport?: { width: number; height: number };
colorScheme?: "light" | "dark" | "no-preference";
timeoutMs?: number;
}加载 ${storybookUrl}/iframe.html?viewMode=story&id=${storyId}，等待 #storybook-root，并报告任何页面错误以及针对该故事的 axe 违规项。
scaffold_react_component{
name: string; // PascalCase
outDir: string; // absolute
variant?: "functional" | "forwardRef" | "polymorphic";
withTests?: boolean; // default true
withStory?: boolean; // default true
props?: Array<{ name: string; type: string; required?: boolean; defaultValue?: string }>;
}代理获得类型化契约。 每个工具都是模型可以内省的 Zod 验证 JSON Schema。
无本地幻觉。 Axe 违规来自真实的 axe-core 引擎，而非正则表达式。包大小来自实际的 zlib 压缩，而非估算值。
可组合。 bundle_budget_check 失败 → 要求代理将最大的文件提取到 page_screenshot → 将图像输入到视觉回归步骤中。一切都通过 MCP 完成。
稳定的接口。 工具在版本更新后保持稳定；您的 .vscode/mcp.json 无需更改。
git clone https://github.com/ashios15/mcp-frontend-tools.git
cd mcp-frontend-tools
npm install
npm run test # 3 unit tests (bundle + tokens + scaffold)
npm run build
npm run inspector # opens MCP Inspector against the built server
node scripts/smoke.mjs # quick stdio tools/list checkMIT © ashios15
用于前端工作的参考 Model Context Protocol 服务器。只需一次安装，即可让任何编码代理（Claude Desktop、Cursor、VS Code、Zed、Continue）真正拥有查看和操作 UI 的“眼睛和双手”：
axe_audit — 针对原始 HTML（通过 jsdom）或实时 URL（通过 Playwright）运行真实的 axe-core 规则引擎。返回按 WCAG 影响程度分组的违规项，并附带修复链接。
page_screenshot — 获取任何 URL 或 CSS 选择器的无头 Chromium PNG 截图，支持视口 / DPR / 配色方案 / waitForSelector 控制。
bundle_budget_check — 遍历 dist/ 目录，计算 gzip（+ 可选 brotli）大小，强制执行全局或每个入口的 KB 预算。提供 CI 就绪的通过/失败 JSON 报告。
design_token_diff — 对两个 W3C DTCG / Style Dictionary 令牌文件进行结构差异对比。报告添加 / 删除 / 修改的令牌，并提供感知 $type 的注释。
storybook_story_run — 通过 iframe.html?id=… 在无头 Chromium 中加载单个 Storybook 故事，进行截图，并仅针对渲染出的组件运行 axe 审计。
scaffold_react_component — 生成带类型的 React 组件（函数式 / forwardRef / 多态 as），以及可选的 Vitest 测试和 Storybook 故事。
所有工具均返回模型可理解的结构化 JSON。无需为每个编辑器编写定制的包装器。
npm i -g @ashishjoshi/mcp-frontend-tools
# Optional — enables page_screenshot, storybook_story_run, and URL-mode axe_audit
npm i -g playwright
npx playwright install chromium需要 Node ≥ 20。即使没有 Playwright，服务器也能启动；如果调用那三个依赖 Playwright 的工具，将返回明确的“安装 playwright”错误。
添加到 ~/Library/Application Support/Claude/claude_desktop_config.json（或 Windows 等效路径）：
{
"mcpServers": {
"frontend-tools": {
"command": "mcp-frontend-tools"
}
}
}设置 → MCP → 添加新服务器：
{
"frontend-tools": { "command": "mcp-frontend-tools" }
}添加到 .vscode/mcp.json：
{
"servers": {
"frontend-tools": { "command": "mcp-frontend-tools" }
}
}npx @modelcontextprotocol/inspector mcp-frontend-toolsaxe_audit{
url?: string; // require playwright
html?: string; // jsdom
tags?: string[]; // default: wcag2a/aa + wcag21aa + wcag22aa + best-practice
selector?: string; // URL mode only
timeoutMs?: number; // default 15000
}返回违规项和不完整规则，包含 impact（影响）、help（帮助）、helpUrl 以及每条规则最多 5 个失败节点示例。
page_screenshot{
url: string;
outPath: string; // absolute; parent dirs auto-created
selector?: string;
fullPage?: boolean;
width?: number; // default 1280
height?: number; // default 800
deviceScaleFactor?: number;// default 2
colorScheme?: "light" | "dark" | "no-preference";
waitForSelector?: string;
timeoutMs?: number;
}bundle_budget_check{
buildDir: string;
budgetKb?: number; // default 250 (gzipped)
perEntryBudgetKb?: Record<string, number>;// key = path substring, longest match wins
ext?: string[]; // default [".js",".mjs",".cjs",".css"]
includeBrotli?: boolean;
}返回每个文件的原始 / gzip / brotli 大小、应用的预算以及 status: "pass" | "fail"。
design_token_diff{
beforePath: string;
afterPath: string;
ignoreKeys?: string[];
}理解 W3C DTCG 结构（$value, $type）。以 $ 开头的组元数据键将被忽略。颜色 / 尺寸的变化会带有 note 注释。
storybook_story_run{
storybookUrl: string; // e.g. http://localhost:6006
storyId: string; // e.g. components-button--primary
screenshotPath?: string;
runAxe?: boolean; // default true
viewport?: { width: number; height: number };
colorScheme?: "light" | "dark" | "no-preference";
timeoutMs?: number;
}加载 ${storybookUrl}/iframe.html?viewMode=story&id=${storyId}，等待 #storybook-root，并报告任何页面错误以及针对该故事的 axe 违规项。
scaffold_react_component{
name: string; // PascalCase
outDir: string; // absolute
variant?: "functional" | "forwardRef" | "polymorphic";
withTests?: boolean; // default true
withStory?: boolean; // default true
props?: Array<{ name: string; type: string; required?: boolean; defaultValue?: string }>;
}代理获得类型化契约。 每个工具都是模型可以内省的 Zod 验证 JSON-Schema。
无本地幻觉。 Axe 违规来自真实的 axe-core 引擎，而非正则表达式。包大小来自实际的 zlib 压缩，而非估算值。
可组合。 bundle_budget_check 失败 → 要求代理将最大的文件提取到 page_screenshot → 将图像输入到视觉回归步骤中。一切都通过 MCP 完成。
稳定的接口。 工具在版本更新后保持稳定；您的 .vscode/mcp.json 无需更改。
npm install
npm run test # 3 unit tests (bundle + tokens + scaffold)
npm run build
npm run inspector # opens MCP Inspector against the built server
node scripts/smoke.mjs # quick stdio tools/list checkMIT © Ashish Joshi
一个 Model Context Protocol (MCP) 服务器，为 AI 助手（Claude、Copilot、Cursor）提供前端开发工具访问权限——包括组件脚手架、包分析、可访问性检查和响应式设计指南。
工具 | 描述 |
| 生成带测试、故事和 CSS 模块的类型化 React 组件 |
| 扫描构建目录以查找过大的 JS/CSS，并报告结果 |
| 对 HTML 进行静态 WCAG 2.2 检查并提供修复建议 |
| 生成响应式 CSS、容器查询和 Tailwind 模式 |
添加到 ~/Library/Application Support/Claude/claude_desktop_config.json：
{
"mcpServers": {
"frontend-tools": {
"command": "node",
"args": ["/path/to/mcp-frontend-tools/dist/index.js"]
}
}
}添加到 .vscode/settings.json：
{
"github.copilot.chat.mcpServers": {
"frontend-tools": {
"command": "node",
"args": ["${workspaceFolder}/mcp-frontend-tools/dist/index.js"]
}
}
}“构建一个带有头像、姓名和个人简介属性的 UserProfileCard 组件”
AI 调用 scaffold_react_component 并返回：
UserProfileCard.tsx — 带 forwardRef 的类型化组件
UserProfileCard.test.tsx — Testing Library 测试
UserProfileCard.stories.tsx — Storybook 故事
UserProfileCard.module.css — CSS 模块
index.ts — 导出入口
“分析我的 dist/ 文件夹以查找包大小问题”
AI 调用 analyze_bundle 并返回一份 Markdown 报告，包含过大的文件、建议和汇总表。
src/
├── index.ts # MCP server setup (stdio transport)
└── tools/
├── index.ts # Tool definitions + router
├── scaffold-component.ts # React component generator
├── bundle-analyzer.ts # Build output analyzer
├── a11y-checker.ts # Static WCAG checks
└── responsive-guide.ts # Responsive CSS pattern generatornpm install
npm run build
npm run inspector # Test with MCP InspectorMIT
Run the axe-core accessibility ruleset against an HTML string (jsdom) or a live URL (Playwright). Returns violations grouped by impact with fix guidance and helpUrl links.
| Name | Required | Description | Default |
|---|---|---|---|
| url | No | Fully qualified URL to audit. Requires playwright installed. | |
| html | No | Raw HTML string to audit (jsdom, no JS execution). | |
| tags | No | axe rule tags to include. Defaults to ['wcag2a','wcag2aa','wcag21a','wcag21aa','wcag22aa','best-practice']. | |
| selector | No | CSS selector to scope the audit (URL mode only). | |
| timeoutMs | No | Default 15000. |
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations provided, so description carries full burden. It discloses the audit scope (axe-core), return format (grouped violations with guidance/links), and that URL mode uses Playwright. No contradictions.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Is the description appropriately sized, front-loaded, and free of redundancy?
Two sentences, no fluff. First sentence states core action and modes, second describes output format. Information density is high.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
No output schema, but description sufficiently hints at return structure (violations grouped by impact, fix guidance, helpUrl). Parameters well described, tool behavior clear. Complete for the complexity level.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
Schema has 100% description coverage. Description adds context beyond schema: clarifies dual mode (url/html), defaults for tags, selector only for URL, timeout default. Adds value.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Does the description clearly state what the tool does and how it differs from similar tools?
Description clearly states the tool runs axe-core accessibility rules on HTML or URL, returns violations grouped by impact with fix guidance and helpUrl links. This is specific and distinguishes it from sibling tools like screenshot or bundler checks.
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Does the description explain when to use this tool, when not to, or what alternatives exist?
Description explains two usage modes (HTML string vs live URL) and mentions prerequisite (playwright for URL). Does not explicitly state when not to use or alternatives, but context with siblings makes it clear.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Walk a build directory, measure raw + gzip (+ optional brotli) sizes per file, and flag files that exceed a global or per-entry KB budget. CI-friendly JSON output.
| Name | Required | Description | Default |
|---|---|---|---|
| buildDir | Yes | Absolute path to the build output directory (e.g. dist, .next/static). | |
| budgetKb | No | Global size budget in KB. Flags any file above this (gzipped). Default: 250. | |
| perEntryBudgetKb | No | Per-file budgets in KB keyed by glob-ish substring match. Matching file is checked against the most specific (longest) matching key. | |
| ext | No | File extensions to include (default: ['.js','.mjs','.cjs','.css']). | |
| includeBrotli | No | Also compute brotli sizes (slower). |
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are provided, so the description carries the full burden. It explicitly states it walks a directory, measures sizes, and flags exceedances. It also mentions CI-friendly JSON output. While it doesn't disclose potential actions (e.g., read-only or any side effects), the described behavior aligns with a read-only check, making it fairly transparent.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Is the description appropriately sized, front-loaded, and free of redundancy?
Two sentences, each purposeful. Front-loaded with the core action ('Walk a build directory...'). No wasted words. The structure is optimal for quick agent comprehension.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
No output schema is present, so the description should clarify the output format. It mentions 'CI-friendly JSON output' but does not specify structure, exit codes, or how budgets are compared. With 5 parameters and a nested object, more detail would help the agent use it effectively. Score 3 reflects adequate but not complete guidance.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
Schema coverage is 100%, so baseline is 3. The description adds minimal value beyond the schema: it mentions 'global or per-entry KB budget' but does not explain the glob matching or default values. The schema already describes each parameter adequately. Thus, the description does not significantly enhance parameter understanding.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Does the description clearly state what the tool does and how it differs from similar tools?
The description uses a specific verb ('Walk') and resource ('build directory') and clearly states the action: measure raw/gzip/brotli sizes and flag budget violations. This distinguishes it from sibling tools like 'axe_audit' (accessibility) and 'scaffold_react_component', which serve entirely different purposes.
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Does the description explain when to use this tool, when not to, or what alternatives exist?
The description clearly implies the tool is for bundle size checks, providing context for use. It does not explicitly state when not to use it or compare with alternatives, but siblings are in unrelated domains, so the context is sufficient. A score of 4 reflects clear context without formal exclusions.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Diff two design-token JSON files (W3C DTCG / Style Dictionary style). Reports added, removed, and changed tokens with $type-aware classification. Useful for PR review of design-system changes.
| Name | Required | Description | Default |
|---|---|---|---|
| beforePath | Yes | Path to the baseline tokens JSON (Style Dictionary / W3C DTCG format). | |
| afterPath | Yes | Path to the new tokens JSON. | |
| ignoreKeys | No | Dot-path keys to ignore (e.g. ['$description','$extensions']). |
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the full burden of behavioral disclosure. It states the tool reports added, removed, and changed tokens with $type-aware classification, which implies a read-only comparison. It does not mention side effects or required permissions, but for a diff tool, the behavior is sufficiently transparent.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Is the description appropriately sized, front-loaded, and free of redundancy?
The description is only two sentences long, front-loading the core action in the first sentence and adding a use case in the second. Every word is informative with no fluff.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
Given the tool has no output schema, the description adequately describes what the diff reports (added, removed, changed tokens). It mentions the input format and the classification approach. The absence of output format details is a minor gap, but overall the description is sufficient for an agent to understand the tool's behavior.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
Schema coverage is 100% with clear descriptions for all three parameters. The tool description adds high-level context (e.g., format, output behavior) but does not provide additional meaning about the parameters beyond the schema. Baseline of 3 is appropriate.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Does the description clearly state what the tool does and how it differs from similar tools?
The description clearly states the tool diffs design-token JSON files, specifies the format (W3C DTCG / Style Dictionary), and lists what it reports (added, removed, changed tokens with type-aware classification). The use case (PR review) distinguishes it from sibling tools (e.g., axe_audit, bundle_budget_check).
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Does the description explain when to use this tool, when not to, or what alternatives exist?
The description explicitly mentions a use case ('Useful for PR review of design-system changes'), which guides when to use it. It does not specify when not to use it or name alternatives, but the context is clear and no sibling tool overlaps with this diffing functionality.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Launch headless Chromium, navigate to a URL, and save a PNG screenshot. Supports element selectors, full-page capture, dark mode, and custom viewports. Requires the optional playwright peer dependency.
| Name | Required | Description | Default |
|---|---|---|---|
| url | Yes | URL to screenshot. | |
| outPath | Yes | Absolute file path to write PNG to. Parent dirs will be created. | |
| selector | No | CSS selector to screenshot instead of the viewport. | |
| fullPage | No | Capture the full scrollable page (default: false). | |
| width | No | Viewport width (default 1280). | |
| height | No | Viewport height (default 800). | |
| deviceScaleFactor | No | DPR (default 2). | |
| colorScheme | No | ||
| waitForSelector | No | Wait for this selector before capturing. | |
| timeoutMs | No |
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description must carry behavioral disclosure. It discloses headless Chromium usage, supports for selectors, full-page, dark mode, and viewports. It also mentions the optional Playwright dependency. Missing details on error handling and default behaviors, but still provides significant transparency.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Is the description appropriately sized, front-loaded, and free of redundancy?
Two sentences, both substantive. First sentence defines core action; second lists key features and a dependency. No redundant or extraneous words.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
Given the tool's complexity (10 parameters, no output schema), the description provides a good high-level overview. It specifies the browser engine, supported features, and a dependency. It could mention return behavior (writes file to disk) or default values, but the schema covers defaults. Overall complete given the context.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
Schema description coverage is 80%, so baseline is 3. The description provides a high-level grouping of features (e.g., 'Supports element selectors, full-page capture, dark mode, and custom viewports') but does not add detail beyond the schema. For the two parameters without schema descriptions (timeoutMs, waitForSelector? waitForSelector has description, timeoutMs does not), the description does not compensate.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Does the description clearly state what the tool does and how it differs from similar tools?
Description clearly states 'Launch headless Chromium, navigate to a URL, and save a PNG screenshot.' It uses specific verbs and a concrete resource. Distinct from siblings like axe_audit or bundle_budget_check, which address different tasks.
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Does the description explain when to use this tool, when not to, or what alternatives exist?
The description implies when to use (when a screenshot of a web page is needed) but does not explicitly exclude alternatives or provide when-not-to-use guidance. Siblings are clearly different, so context is clear.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Write a TypeScript React component, optional test, and optional Storybook story into outDir. Supports functional, forwardRef, and polymorphic (as prop) variants.
| Name | Required | Description | Default |
|---|---|---|---|
| name | Yes | ||
| outDir | Yes | Absolute directory to write the component files into. Created if missing. | |
| variant | No | ||
| withTests | No | ||
| withStory | No | ||
| props | No |
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations provided, so description must disclose behavioral traits. It mentions file creation and that outDir is created if missing, but does not state whether files are overwritten, side effects, or required permissions. This is insufficient for a write operation.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Is the description appropriately sized, front-loaded, and free of redundancy?
The description is a single sentence, concise and front-loaded, but could benefit from a second sentence to improve clarity without significant length increase.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
With 6 parameters, no output schema, and no annotations, the description is incomplete. It does not explain return value, error conditions, or full behavior of the props parameter.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
Schema description coverage is low (17%), and the description does not explain parameters like variant, props, withTests, withStory. It mentions variants but does not elaborate on differences between functional, forwardRef, polymorphic.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Does the description clearly state what the tool does and how it differs from similar tools?
The description clearly states it writes a TypeScript React component with optional test and Storybook story, and supports three variants. This distinguishes it from sibling tools which are unrelated (auditing, budget, screenshots).
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Does the description explain when to use this tool, when not to, or what alternatives exist?
The description provides basic context but lacks explicit when-to-use or when-not-to-use guidance. Since siblings are in different domains, the need for alternatives is less, but no prerequisites or exclusions are mentioned.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Load a single Storybook story in headless Chromium via iframe.html, optionally screenshot it, and run an axe-core audit against the rendered output. Requires playwright.
| Name | Required | Description | Default |
|---|---|---|---|
| storybookUrl | Yes | Base URL of a running Storybook, e.g. http://localhost:6006. | |
| storyId | Yes | Story id as it appears in the URL (e.g. 'components-button--primary'). | |
| screenshotPath | No | If set, save a PNG of the rendered story to this absolute path. | |
| runAxe | No | Run an axe-core audit of the rendered story (default true). | |
| viewport | No | ||
| colorScheme | No | ||
| timeoutMs | No |
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description must cover behavioral traits. It discloses the main actions (load, screenshot, audit) and the need for Playwright, but lacks details on side effects like browser resource usage, error handling, or that it returns axe results.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Is the description appropriately sized, front-loaded, and free of redundancy?
Two sentences with no fluff. The purpose and key requirement are front-loaded in the first sentence, making it efficient.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
The tool has 7 parameters, nested objects, and no output schema. The description omits return values, parameter interactions, and behavioral details like error scenarios or required environment setup, making it incomplete for a complex tool.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
Schema description coverage is 57%, so the description should add meaning, but it does not explain parameters beyond the schema. It only gives a generic summary, leaving parameter nuances (e.g., viewport, colorScheme, timeoutMs) solely to the schema.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Does the description clearly state what the tool does and how it differs from similar tools?
The description clearly states it loads a single Storybook story via headless Chromium, with optional screenshot and axe-core audit. It distinguishes from siblings like page_screenshot (general) and axe_audit (general audit) by focusing on Storybook stories.
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Does the description explain when to use this tool, when not to, or what alternatives exist?
The description implies usage for testing Storybook stories but does not explicitly contrast with sibling tools or specify when not to use it. It only mentions a prerequisite (Playwright), not exclusion criteria.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Recent tool additions, removals, and schema changes observed during successful MCP inspections.
v2.0.0axe_auditbundle_budget_checkdesign_token_diffpage_screenshotscaffold_react_componentstorybook_story_runScored across 6 tools
Each tool targets a distinct frontend concern: accessibility auditing, bundle sizing, design token diffs, page screenshots, component scaffolding, and Storybook testing. No two tools could be confused.
All tool names follow a consistent 'object_action' or 'domain_action' pattern with lowercase underscores (e.g., axe_audit, design_token_diff). No mixing of conventions.
Six tools is an appropriate size for a frontend utility toolkit. Each tool provides a distinct, useful function without being overwhelming or too sparse.
The set covers key frontend tasks: accessibility, performance, design tokens, component generation, and testing. A minor gap is the lack of a linting or formatting tool, but the surface is coherent for its scope.
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